The present invention relates to a switch device including a switch member that is activated when pushed.
In the prior art, a remote controller that remotely operates a controlled subject, such as a vehicle door, includes a switch device that switches the state of a switch contact when pushed. In particular, an electronic key such as a remote control key includes a push-type switch device that activates a contact when a button is pushed (refer to, for example, Japanese Laid-Open Patent Publication No. 2008-181791).
Referring to FIG. 14, the switch device described in Japanese Laid-Open Patent Publication No. 2008-181791 includes a substrate 53 and a switch member 54 (switch contact) arranged on the substrate 53. A rubber sheet 55, for example, is arranged on the switch member 54. A button 52, which can be pushed, is arranged in an opening 51 of a case 50. In the switch device, the button 52 is supported at only one location, which is the central part of the rubber sheet 55 (one-point support structure).
A pushing element 56 projects downward from the lower surface of the button 52 and contacts the rubber sheet 55.
In the switch device that has the one-point support structure described above, when the button 52 is pushed, the button 52 may incline or sway about the pushing element 56. This results in uncomfortable pushing of the button 52 and is thus undesirable. Further, when the button 52 is pushed, as the pushing force increases, the reaction force acting against the pushing force does not initially increase as much as the pushing force. Thus, the initial pushing force and the movement of the button 52 are not in a linear relationship. As the pushing force is further increased by a certain amount and the reaction force becomes large, the central part of the rubber sheet 55 finally starts to move downward. Thus, the operation feel of the button 52 is not constant, which is undesirable. The same problem related to the operation feel also occurs when the button 52 does not have the pushing element 56, and part of a resin member supports the lower surface of the button 52 instead.